1. Field of the Invention
The present invention relates generally to container security and, more particularly, to sensor communication within a shipping container security system.
2. Background of the Invention
In today's efficiency conscious transportation environment, there is a strong need to cost-effectively and accurately track the location of containers, and groups of containers shipped together as a lot, at various stages during the supply chain. This need exists both in the United States and abroad.
Despite the strong need few solutions, if any, have been able to provide the accuracy needed to suit the transportation industry and the government agencies charged with monitoring shipments. This lack of an acceptable solution is due to many factors which complicate interstate and international shipping. Shipping containers are used to transport most of the commerce entering, leaving, and transiting or moving within the United States. It is estimated that there are over 6 million containers moving in global commerce. Shipping containers have revolutionized the transportation of goods by greatly reducing the number of times goods must be loaded and unloaded during transport. However, at the same time, this same advantage has created a major problem in that it is very difficult to monitor and track the location of each container during transport and in most cases the containers look very similar, so it is virtually impossible to ascertain the contents of containers without opening them up to inspect them.
To adequately monitor containers using electronic means an array of many different sensor types is required. These sensors may be temperature, light, acoustics and vibration, radiation, chemical, door opening, tampering, and many more. In many ways the more sensors that are available in the container monitoring system, the more intelligent the system may be to detect a wide range of tampering and potential threats. Unfortunately, the addition of many sensors to a monitoring system can quickly complication implementation and escalate cost to a level where the system is not practical.
Also, for the system to operate properly various sensors often need to be placed in specific locations and these are not always nearby the device which controls and interfaces to these sensors. In these cases, it is highly impractical for devices to be wired or tethered in some fashion, and a wireless interface is the only reasonable approach for connectivity to occur. At the same time, a wireless interface adds complexity to the system, and field technicians can often spend hours attempting to interface sensors with the associated control devices.
Thus, a solution is needed for simplifying addition of sensors to a container monitoring system using an open architecture and standards based design. This concept has been used in the computer industry in recent years. For example, interfacing to a printer or scanner even as recently as a few years ago was often a cumbersome task. Specific drivers needed to be loaded in particular sequence and anyone who has used a computer in recent years can remember hours of struggling with various peripheral devices. More recently, computer physical interface and software interfaces have become more sophisticated as to provide the system with the ability to automatically recognize these devices and seamlessly integrate them. If one were to plug in most devices into a computer USB port today, the compute would automatically recognize theses devices and moments after plugging in the cable they are ready to use.
The same concept applies to a container security system. Most frequently, different sensors are built by different manufacturers, but a common interface standard would alleviate many of the engineering, installation, and maintenance issues associated with complex container monitoring and security systems.